Golang vs Node.js slices

lol.go

package main

import "fmt"

func main() {
	a1 := []int{1, 2, 3, 4, 5}
	a2 := a1[1:3]
	a2 = append(a2, 10, 20)
	fmt.Println(a1) // [1 2 3 10 20]
	fmt.Println(a2) // [2 3 10 20]

	// Slice is a reference until it is not, lol
	// append beyond capacity will make a copy:
	// a2 = append(a2, 10, 20, 30)
}

lol.js

let a1 = [1, 2, 3, 4, 5];
let a2 = a1.slice(1, 3);
a2.push(10, 20);
console.log(a1); // [ 1, 2, 3, 4, 5 ]
console.log(a2); // [ 2, 3, 10, 20 ]

Src: https://x.com/siberex/status/1952024924521890263